Despite lower than expected album sales and even recent proof of lip syncing, Britney Spears’ Piece of Me Concert has remain unscathed.

The two year residency has just sold out its entire second leg– bringing the total amount grossed to $10.9 million over 16 concerts.

Many were skeptical Spears would be able to hold her own against other Vegas acts such as Cirque du Soliel and Celine Dion. As well, her recently released Britney Jean only hit a #12 peak position on Billboard, becoming her most poorly performing album to date.

However, Britney’s fans have come out to support her tour, as well as celebrities Selena Gomez, Katy Perry, Miley Cyrus and two weeks ago, Lady Gaga. Spears, who still holds the record for the highest one-week sales for a female artist (2000’s Oops…I Did it Again, 1,319,000 sold) shows no sign of her ticket sales slowing as her next date kicks off March 25th, with limited seats available.